Troubleshooting
SiBE06-708_A
121
Service Diagnosis
4.24 Refrigerant Shortage
Remote
Controller
Display
U0
Method of
Malfunction
Detection
Refrigerant shortage detection I:
Refrigerant shortage is detected by checking the input current value and the compressor
running frequency. If the refrigerant is short, the input current is smaller than the normal value.
Refrigerant shortage detection II:
Refrigerant shortage is detected by checking the discharge pipe temperature and the opening of
the electronic expansion valve. If the refrigerant is short, the discharge pipe temperature tends
to rise.
Refrigerant shortage detection III:
Refrigerant shortage is detected by checking the difference between suction and discharge
temperature.
Malfunction
Decision
Conditions
Refrigerant shortage detection I:
The following conditions continue for 7 minutes.
<25/35 class>
Input current × input voltage
≤
× output fre
Output frequency >
<50 class>
Input current
≤
× output fre
Output frequency >
Refrigerant shortage detection II :
The following conditions continue for 80 seconds.
Opening of the electronic expansion valve
≥
Discharge pipe temperature >
× target discharge pipe tempe
(–)
(W)
(Hz)
640/256
0
55
(–)
(A)
(Hz)
18/1000
0.7
55
(pulse)
(–)
(°C)
RK(X)S25/35F2V1B
480
255/256
30
RK(X)S25/35G2V1B
RK(X)S25/35G2V1B9
480
128/128
30
RK(X)S50F2V1B
RK(X)S50G2V1B
480
128/128
Cooling: 20
Heating: 45
